Printing/Showing elements of tensors

[Tucker Manton]

Hi All,

I am working in a particular chart and am working with various curvature tensors. MetricCompute gathers all the basic curvature tensors in their covariant form, and it's straightforward to print/show the elements of each covariant quantity. I would like to be able to compute and print out the contravariant form of the curvature tensors, such as $R^{\mu\nu}$, but am struggling to come up with the correct commands. Additionally, I would like to define certain combinations of the curvature tensors in such a way that I can print/show it's elements. Attached is an example of an attempt to show the contravariant Ricci tensor and an attempt to show elements of a tensor defined as $X_{\mu\nu}=R_{\mu\alpha}R^{\alpha}_{\nu},$ over a spatially flat isotropic FRW metric. 

Any help would be greatly appreciated, thank you!

Tucker

[Cyril Pitrou]

Dear Tucker,

I think you need to use "ChangeComponents".

See example attached where I tried to solve your problem/

Regards,

Cyril

---------------

--
You received this message because you are subscribed to the Google Groups "xAct Tensor Computer Algebra" group.
To unsubscribe from this group and stop receiving emails from it, send an email to xact+uns...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Tucker Manton]

Cyril,

Thank you very much for your prompt reply, your attached notebook does exactly what I need. 

Best regards,

Tucker